Re: [PATCH v2 RESEND] usb: dwc3: core: Fix ULPI PHYs and prevent phy_get/ulpi_init during suspend/resume

[Todor Tomov <todor.tomov@linaro.org>]

Hi Felipe,

On 16.11.2018 19:01, Todor Tomov wrote:
> Hi,
> 
> On 15.11.2018 10:09, Felipe Balbi wrote:
>>
>> Hi,
>>
>> Todor Tomov <todor.tomov@linaro.org> writes:
>>
>>> Hello,
>>>
>>> After I apply this patch on 4.14 (or receive it with 4.14.70) I see a regression with
>>> the Qualcomm QUSB2 phy driver. I'm testing on a Dragonboard 820c.
>>> In boot log I get:
>>>
>>> [    4.525502] phy phy-7412000.phy.6: QUSB2PHY pll lock failed: status reg = 0
>>> [    4.529232] phy phy-7412000.phy.6: phy init failed --> -16
>>> [    4.536170] dwc3 7600000.dwc3: failed to initialize core
>>> [    4.541743] dwc3: probe of 7600000.dwc3 failed with error -16
>>> [    4.549979] phy phy-7411000.phy.5: QUSB2PHY pll lock failed: status reg = 0
>>> [    4.552843] phy phy-7411000.phy.5: phy init failed --> -16
>>> [    4.559606] dwc3 6a00000.dwc3: failed to initialize core
>>> [    4.565181] dwc3: probe of 6a00000.dwc3 failed with error -16
>>>
>>> I can provide a full log if needed.
>>
>> please do. Also, try mainline and let us know if the problem
> 
> This is the full log on 4.14.69 + this patch: https://paste.ubuntu.com/p/N5WdHw47QC/
> I also managed to get a log from 4.20.0-rc2 and I see the same error: https://paste.udwc3_phy_setupbuntu.com/p/jz6fvYyZh6/
> 
>> persists. Why do you get -EBUSY from the PHY driver?
> 
> Maybe I could have proposed a fix if I knew but I don't know.

I have done some debugging but I still cannot understand it completely.

What I see is that if the PHY interface is configured first (dwc3_phy_setup)
then the PHY init (qusb2_phy_init called by dwc3_core_soft_reset) fails
with "pll lock failed". If we move dwc3_phy_setup after dwc3_core_soft_reset
as it was before this patch, it works.

Do you have any ideas why this happens or how to solve it?

Thank you.
Best regards,
Todor